Operating jig for calorimeter bomb



SePt- 2, 1958 R. w. STOER-rz j 2,849,791

OPERATING JIG FOR CALORIMETER hBOMB l v y 3 She-'ets-Sheet 1 Filed Deo. 5, 1952 Sept- 2, 1958 Rw. STQERTZ 2,849,791 OPERATING JIG FOR CALORIMETER BOMB Filed neo. 5. 1952A :s sheets-sheet 2' /Pafr mJy-amera United States Patent O wil GPERATING .HG FR CALORE/DETER BOMB Robert W. Stoertz, Charleston, S. C., assignor to West Virginia Pulp and Paper Company, New York, N. Y., a corporation of Delaware Application December 5, 1952, Serial No. 324,385'

2 Claims. (Cl. 29-240) This invention relates to operating jigs for closing and opening calorimeter bombs. A calorimeter bomb may desirably consist of a stainless steel generally spherical vessel, split horizontally through the middle. To prevent the escape of gasesthe two halves of the bomb are assembled and sealed by means of a large stainless steel locking nut which also forms a part of the bomb. The

v bottom half of the bomb is iirst charged with a measured quantity of combustible material to be tested, and the bomb parts are then assembled. Oxygen is introduced into the bomb, desirably at a pressure of 375 pounds per square inch, after which the material charge is ignited and the heat of combustion determined in the usual calorimeter. The bomb is then vented and disassembled.

According to conventional practice the bomb is made up tight with a three-foot Spanner wrench lapplied to lugs on the nut to very nearlyy the limit of the operators strength. Adequate closing has been found diicult, and in some cases impossible, with operators of ordinary strength. To prevent leaking, it is necessary each time to apply a closing torque slightly in excess of the torque applied at the last previous closing-this because 'of the progressive deterioration of a lead sealing washer which is used, Application of a uniform closing torque is nearly impossible as different operators are Inot equally strong. Even the strength of the same operatorrvaries fromtime to time. Opening ofthe bomb is almost impossible without the use of a sledge hammer to apply an impact along with the torque of the wrench. The use of a large heavy wrench forced very nearly to the limit of t-he strength of the operator constitutes a safety hazard of some importance.

lt is a primary object of the present invention to provide a bomb closing and opening jig in which the lower half of the bomb may be held securely against turning, and in which multiplication gearing is provided for transmitting the torque of a wrench to the closing nut with a high mechanical advantage, to enable the nut to be turned up tight without straining the operator.

it is a further object to provide a jig for the above purpose which gives the user a choice of operating speeds or mechanical advantages, sovthat the preliminary closing and the final opening can be performed rapidly Vwhile the final closing and the preliminary opening can be performed powerfully;

lt is still another object to provide a jig of the kind referred to which is of compact, simpleand kinexpensive construction, and which is sturdy, dependable and etlicient in service. v s

Other objects and advantages will hereinafter appear. in the drawing forming part of this specication,

Figure l is a-plan View of a novel jig embodying features of the invention;-

f Figure 2 is a sectional View taken upon the line 2-,2 of Figure 1, looking in the direction of the arrows;

"` Figure 3'i's a'detail view 'of 'an operating knob or finger Zigfii Patented Sept. 2, 1958 piece adapted to be applied to one of the available input gears of the jig;

Figure 4 isa sectional view taken upon the line 4-4 of Figure l, looking in the direction of the arrows;

Figure 5` is a sectional view taken upon the line 5 5 of Figure 1, looking in the direction of the arrows;

Figure 6 is a sectional View similar to Figure 2 but with the bomb in place in the jig;

Figures 7 and 8 are views in elevation, respectively of the upper and lower chamber forming members of the bomb;

Figure 9 is a view-in elevation of a clamping nut which also forms part of the bomb;

Figure l0 is an enlarged, detail, fragmentary view showing rims of the upper and lower bomb forming members in opposed but separated relation;

Figure 11 is a viewl loo-king obliquely down on the structure shown in Figure 1; and

Figure l2 is a view in vertical section of the assembled bomb removed from the jig.

The illustrative bomb comprises upper and lower complementary metallic chamber forming members 1t? and 12, and a clamping nut 14. The lower member 12 is in the form of a cup having an external thread 16 on its upper outer margin and a series of equally spaced external lugs 18 (three as shown) disposed around its body below the threaded margin. The upper edge of the member 12 is grooved to receive a lead sealing washer 12a. A plug 11 is threaded into the side, of the cup 12 and supports, through insulation 13, a conductive rod 15. T he rod 15, through a conductive bracket 17, supports a pan 19 into which a measured fuel charge is placed. A conductive arm 21 of the bracket17 is connected through a wire 23 with an internal lug 25. The outer end of the rod 15 is formed to receive removably a tapered conductive terminal pin of a first electrical conductor (not shown).

The upper member 10 'is dome-shaped. It is provided with a lowercircular rib 20 adapted to t into the groove of the cup and to bear against the lead washer 12a. The rib 20 is formed with a groove 20a for receiving a complementary rib 2Gb onfthe washer. l

The nut 14 is formed with anrinternal iiange 22 which is adapted to surround the body of the member 10 and to bear downward against the flange 2t). The nut 1d also includes an internal thread 24 at its lower margin for cooperating with the thread 16 of the lower member 12 for pressing the members 10 and 12 forcibly together. Lugs 26 are provided externally on the nut 14, there being three equally spaced lugs on the illustrative nut. The lugs 18 and 26 are adapted to cooperate with relatively movable parts of the jig.

A fitting 28, threaded onto the top of the member iii, has a passage formed through it 'for the admission of oxygen and the discharge of combustion gases. A needle valve 30, threaded downward through the iitting 28, may be turned into position to open or to close the passage. A nipple 32 connects'with a side passage of the fitting 28. The nipple may be connected to a hose for delivering oxygen into the bomb when the needle valve 30 is open, and

the needle valve may then be closed and the hose detached from the nipple. The upper end of the needle valve is formed to receive removably fa tapered terminai pin of a second electrical conductor. Details of the conductors and the tiring circuit are not illustrated, since they form no part of the present invention.

The illustrative bomb operating jig comprises a thick, rectangular basev plate 34 which has a large circular opening 36 formed through it. It is provided with bolt holes 35, through which it may be attached to a board or table. A sleeve 38 is fitted onto the plate 34. The sleeve 38 has a bottom rim or flange portion 40 received in the opening 36 of the base plate 34, and a circumferential flange 42 disposed to rest upon the plate 34 in the area bordering said opening. The flange 42 is generally circular, but along one side hasa straight vertical boundary. The collar 38 is secured to the base plate 34 by headed screws 44 whose shanks pass downward through the ange 42 and into the plate. The sleeve 38 includes at its upper end an internal flange 46 of substantial thickness through which vertical channels 48 are formed, there being three of the channels at equally spaced intervals. The flange is thus divided to form a series of internal abutments or holding segments for cooperating with the lugs 18 of the lower calorimeter member 12. A fourth internal channel 48a is provided to accommodate the head of the plug 11. A ring 50, pressed upward into the sleeve 38 against the flange 46, closes the lower ends of the channels 48.

The sleeve 38 is externally rabbeted, and receives in the rabbetthe vertical cylindrical wall of a flanged bearing sleeve or bushing 52, desirably of lbrass. An inturned flange of the bushing 52 rests upon the upper end of the sleeve 38. A gear 54 having external teeth 56 is formed internally with a rabbet 57, which Yrotatively engages the bearing bushing 52. The upper portion of the gear 54 is formed internally with three equally spaced vertical channels 58. The channels divide the inner portion of the gear into a series of internal driving segments for cooperation with the lugs 26 of the nut 14. The teeth of gear 54 mesh with the teeth of a smaller gear 60, by which the gear 54 is driven. The gear 60 forms part of a gear unit 62.

The unit 62 comprises complementary supporting blocks 64 and 66 which meet in a vertical plane, but which are recessed and grooved to receive between them various gears and shafts of the unit. The blocks 64 and 66, when assembled with one another and withthe other parts, are secured to the base plate 34 by vertical headed `screws 68, and are secured to one another by horizontal headed screws 7i) whose shanks are passed freely through the block 66 and threaded into the block 64. The block 64 engages the flat boundary of 'the ange 42. It is Aalso cut out to overlie `a portion of the gear 54.

The gear 60 is made fast upon a vertical shaft 72 which extends down between the 'blocks 64 and 66 and into a bearing bushing 74. The bushing 74 is mounted in the base plate 34. The shaft 72 has an enlarged upper end portion 76 formed with a pair of pin receiving bores 78. A knurled knob 80 (Figure 3), having a pair of projecting pins 82 extending from its lower end, may be detachably applied to the upper end of the shaft 72 for turning the shaft and the gear 60.

The shaft 72 also has fast upon it a -gear 84 through which the shaft may be operated powerfully from other gearing. The gear 84 is in mesh with smaller driving gears 86 and 88 which are of different sizes.

The gear 36 is made fast upon a .vertical shaft 89 which extends downward between theblocks 64 and 66 land into a brass bushing 90 of the base plate 34. The shaft 89 also extends through a brass bearing sleeve 92 which is secured between the blocks 64 and 66. The shaft 89 has an enlarged head 94 in which a wrench socket 916 is formed. When a wrench is applied to the shaft head 94 the drive is from the shaft 89 through gears 86 and 84 to the shaft 72, and thence through 'gear 60 `to gear 54. The mechanical advantage `of gear 86 relative to gear 54 in the illustrative jig is 9.5 to 1.

The gear 88 is integral with shaftV 98 whose lower end is rotatably received in a brass bearing bushing 100 of the base plate 34. A complementary, co-axial yshaft section 161 `is made separate from the shaft 98 for assembly purposes, but has tongue and groove vconne-ction with the shaft 98 so that these aligned shaft elements operate as one` The shafts 98an'cl 101 both have bearing in a brass bearing sleeve 102 which is secured between the blocks 64 and 66. The shaft 101 -has an enlarged head 104 which is formed with awrench socket 4f 106 like the socket 96 of the shaft 89. When a wrench is applied to the shaft head 104 the drive is from the shaft 101 through shaft 98 and gears 88 and 84 to the shaft 72, and thence through gear to gear 54. The mechanical advantage of gear 88 relative to gear 54 in the illustrative jig is 14 to 1.

When a test is to be made, a measured quantity of cornbustible material is placed in the pan 19 of the lower bomb member 12, see Figure 12, the upper bomb member 18 is placed on the lower bomb member with the rib 28 bearing against the lead sealing washer 12a, and the nut 14 is then screwed by hand onto the thread 16 of the lower member 12. The bomb is then placed in the jig with the lugs 18 partly entering the channels 48 and with the lugs 26 resting on the 4gear S4. The knob 80 is then applied to the upper end of the shaft 72 and turned to rotate the gear 54 until the channels 58 come into registration with the lugs 26, whereupon the bomb drops into the position illustrated in Figure 6. The knob may be further turned to tighten the nut 14 on the bomb member 12 so long as the turning is easy. A torque wrench 110 is then applied to the upper end of shaft v101 and turned to screw the nut 14 down onto the member 12 forcibly enough to thoroughly seal the joint between the members i@ and 12.

When this vhas been done the bomb is lifted freely out of the jig and subsequently charged with oxygen, the needle valve 30 is closed, and the oxygen hose is detached from the nipple 32. Electrical connections from a firing circuit (not shown) to the rod 1S and the valve 30 yare established. The bomb is then submerged in a measured quantity of water of known temperature, as is well understood, and the firing circuit is closed to tire the bomb. The hot bomb 'causes the water temperature to rise until a steady temperature has been attained, whereupon the water temperature is noted and the -bomb is withdrawn, dried, and returned to the jig. Here the needle valve may be opened slighly to vent the bomb Igradually, after which the wrench 110is again applied to the shaft 181 and turned to start the opening of the bomb. When thev nut 14 has been su`1- ciently freed to make operation through the knob 86 and ythe shaft 72 feasible, the latter connection is effected,

and the backing off of the nut is continued more rapidly by that means. The nut may be completely detached through operation of the knob, or the bomb may be removed from the jig and the final detachment of the nut may be effected by manual turning.

A schedule for repetitive bomb asesmbly should be worked out for each apparatus. For the bomb illustrated herein only the shaft 161 is utilized in the final closing ,and preliminary opening operations. After a new lead sealing Washer 12a has been installed a torque of 55 foot pounds should be applied. This'can be determined by using a torque `wrench c-f Ia known type which embodies means for indicating the torque in foot pounds. At each following assembly the torque should be increased by 21/2 foot pounds until a maximum value of 85 foot pounds is reached. At that point the lead washer should be renewed and the sequence repeated, starting again with 55 foot pounds for the first assembly. The torque required to losen the nut after au explosion is usually from lO to 15 foot pounds greater than the torque employed in effecting the assembly.

Since a power multiplication factor of 14 is introduced by the jig the operation is well within the physical capacity of any operator. No pounding is required, and the operator can watch the wrench indicator and nicely adjust the closing pressure in accordance with his observation.

It will be noted that the shaft 89 is not used at all in connection with the bomb herein illustrated. When a different bomb is to be operated upon requiring less torque than the one herein illustrated, the shaft 89 is useful, since, with its 'lower mechanical advantage, it is capable of higher speed oper-ation.

I have described what I believe to be the best embodiments of my invention. I do not Wish, however, to be conned to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. A closing and opening jig for a calorimeter bomb which comprises two relatively rotatable threaded members both formed with external driving lugs, one of said members having an external diameter larger than the other, said jig comprising, in combination, a stationary base, a stationary bomb supporting sleeve rigidly secured to the base and having inwardly facing channels disposed axially of the sleeve upon a comparatively smal-l radius in position to receive the lugs of the smaller diameter relatively rotatable bomber member, and thereby lock said smaller diameter bomb member positively against substantial rotation in either direction, a ring 'gear coaxial with the stationary sleeve and rotatively mounted thereon, said gear having a shouldered sleevevportion provided with inwardly facing channels disposed above the stationary sleeve and upon a comparatively large radius in position to receive the lugs of the larger diameter relatively rotatable bomb member to force said larger diameter member positively to turn with the gear in either of two opposite directions, means carried by said base and coacting With said shouldered portion for securing said gear and gear sleeve portion on said stationary sleeve against spatial displacement relative thereto, and operating means for said gear including power multiplying Igearing supported from said base and connected to drive said gear rotationally in opposite directions relative to said sleeve.

2. A jig as set forth in claim 1, wherein said operating means gearing comprises a gear train, a rst input shaft connected to one gear in said train providing a relatively high speed low power input, and a second input shaft connected to a second gear in said train providing a relatively low speed high power input.

References Cited in the le of this patent UNITED STATES PATENTS 1,188,626 Cofsky June 27, 1916 1,326,817 Yamane Dec. 30, 1919 1,343,667 Evensen June 15, 1920 1,507,654 Allison Sept. 9, 1924 1,865,038 Oldham June 28, 1932 1,897,465 Coon Feb. 14, 1933 2,473,507 Bullard June 21, 1949 2,569,509 Wells Oct. 2, 1951 2,762,544 Davis Sept. 11, 1956 FOREIGN PATENTS 593,276 Great Britain Oct. 13, 1947 

